Leonardo DiCaprio & Vittoria Ceretti Take a Dip Off Yacht in Saint-Tropez

Leonardo DiCaprio and Vittoria Ceretti are one of Hollywood's hottest couples ... so, they decided to go for a dip to cool off in a rare vacation for the pair.

The actor and his model GF hit the water off the coast of celebrity vacation hot spot Saint-Tropez in a couple revealing outfits ... with Leo wearing board shorts and VC baring her buns in a thong-style bikini.

Leo was dripping with water while having a chat with Vittoria on deck ... and, the two were spotted standing at the edge of the deck, looking down into the waves.

Unclear if Vittoria got in the water ... but, she seemed to enjoy hanging out with her man either way -- along with Italian mogul Tommaso Buti, who was also onboard the ship.

Leo and Vittoria are enjoying a European vacation, which dates back to their appearance at Jeff Bezos and Lauren Sanchez Bezos's wedding in Venice, Italy at the end of June.

Leo tried to keep a low profile in his normal black hat and face mask ... but, his better half stunned in a series of outfits during the multiday ceremony.